/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
  * 
  * SPDX-License-Identifier: Apache-2.0 
  * 
  * Change Logs: 
  * Date           Author       Notes 
  * 2021-09-03     RT-Thread    first version 
  */
  #include <stdio.h>
  #include <stdarg.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <stdarg.h>
  #undef errno
  extern int errno;
  extern int _end;
  caddr_t _sbrk(int incr)
  {
      static unsigned char *heap = NULL;
      unsigned char *prev_heap;
      if (heap == NULL)
      {
        heap = (unsigned char *) &_end;
      }
      prev_heap = heap;
      heap += incr;
      return (caddr_t) prev_heap;
}

int link(char *old, char *new)
{
    return -1;
}

int _close(int file)
{
    return -1;
}

int _fstat(int file, struct stat *st)
{
    st->st_mode = S_IFCHR;
    return 0;
}

int _isatty(int file){
    return 1;
}

int _lseek(int file, int ptr, int dir){
    return 0;
}

int _read(int file, char *ptr, int len){
    return 0;
}

void abort(void){
    /* Abort called */    
    while (1)    
        ;
}